Chicken serum albumin, i.e., hen egg alpha-livetin, is a recognized food allergen in chicken meat and hen eggs. Currently, there is no immunoassay available for its detection from food matrices. The characterization of chicken serum albumin-specific antibodies and the extraction of the target protein are essential for immunoassay development. One monoclonal antibody (mAb), 3H4, was used in this study due to its selectivity to a linear epitope on avian serum albumin. To study the extraction of chicken serum albumin, phosphate-buffered saline (PBS) with two additives, i.e., sodium dodecyl sulfate (SDS) and dithiothreitol (DTT), was used for its extraction from chicken blood plasma and hen egg yolk. SDS and DTT improved the chicken serum albumin's recovery and enhanced chicken serum albumin's immunodetection. In addition, chicken serum albumin retained the best solubility and immunoreactivity after heat treatment in a neutral condition. It experienced degradation and aggregation in acidic and alkaline conditions, respectively. Overall, PBS containing 0.1% SDS and 1 mM DTT (pH 7.2) was a better extraction buffer for chicken serum albumin. However, the complexity of the food matrix and elevated temperature could reduce its solubility and immunoreactivity.
Keywords: alpha-livetin; chicken serum albumin; extraction buffer; linear epitope; pH effect; reducing agent; thermostability.